CoPtCr alloys are known to be useful for longitudinal magnetic recording. In such media, the hexagonal close packed (HCP) crystalline structure of the cobalt alloy is formed so that the c-axis, i.e., the [0001] axis, of the cobalt alloy film is in the plane of the film or has a large component in the plane of the film. Such an alloy is described in U.S. Pat. No. 4,789,598, which discloses that CoPtCr alloys with a chromium content greater than 17 atomic percent exhibit substantially reduced media noise at high recording densities. This improvement is reflected in the alloy's larger signal-to-noise ratio (SNR). In general, this improvement in SNR continues as the chromium concentration of the alloy is increased. Unfortunately, chromium concentrations greater than 22 atomic percent can also reduce the Curie temperature and coercivity (H.sub.c) of the alloy. Because high coercivity is a vital characteristic of high density magnetic recording media, the decrease in coercivity of CoPtCr alloys with high chromium content is a major obstacle to improving upon the low-noise characteristics of such alloys. For the foregoing reasons, there is a need for a thin film magnetic recording medium that matches or exceeds the desirable SNRs of high-chromium CoPtCr alloys while maintaining high coercivity and thermal stability.